(a) Field of the Invention
The present invention relates to a thin film transistor array panel.
(b) Description of the Related Art
A display device usually includes a thin film transistor associated with each pixel, for switching voltages to be applied to the pixel on and off. The thin film transistor includes a gate electrode to which a switching signal is applied, a source electrode to which a data voltage is applied, and a drain electrode outputting the data voltage, thereby forming a switching element. Also, the thin film transistor includes an active layer as a channel layer overlapping the gate electrode, the source electrode, and the drain electrode. The active layer includes amorphous silicon as a semiconductor material.
However, as the size of a display becomes larger, thin film transistors having higher electron mobility are required. In particular, the amorphous silicon currently used as the active layer has low electron mobility, and is manufactured by vacuum-based depositing instruments, such as CVD, sputtering, etc., which are expensive.
Accordingly, it may be desirable to develop an oxide semiconductor with a high electron mobility that can be easily manufactured and that can be applied with coating process or printing process of low cost. Also, a method that increases current mobility speed by forming wiring using a metal having low resistivity has increased.
However, when forming the electrode of the thin film transistor using a metal that has a low resistivity, an unnecessary reaction is generated between the oxide semiconductor and the metal of the electrode. As a result, adherence between the oxide semiconductor and the metal of the electrode is low, such that they may be separated from each other. This can increase the resistivity of the electrode and the performance of the semiconductor is deteriorated.
The above information disclosed in this Background section is only for enhancement of understanding of the background and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.